nps-2143 is a novel and selective antagonist of casr (ca2+-sensing receptor) with the ec50 value of 4.27mm for [ca2+]o [1].calcilytics nps-2143 has been reported to diminish the sensitivity of the casr for [ca2+]o, resulting in an attenuated signal transduction in vitro and increased secretion of pth in vivo. in addition, the ec50 values of nps-2143 are 4.27, 1.56, 1.61, 2.46, 2.07 and 3.15mm for the wild-type casr, mutant casr (t151r, p221l, e767q, g830s, and a844t), respectively. apart from these, in hek 293t cells expressing casr, nps-2143 has been revealed to inhibit the [ca2+]o-induced cytosolic calcium signal in a concentration-dependent manner [1]..
[1] letz s1, rus r, haag c, dörr hg, schnabel d, möhlig m, schulze e, frank-raue k, raue f, mayr b, schöfl c. novel activating mutations of the calcium-sensing receptor: the calcilytic nps-2143 mitigates excessive signal transduction of mutant receptors. j clin endocrinol metab. 2010 oct;95(10):e229-33.
